Íslenskar landbúnaðarrannsóknir - 01.03.1970, Blaðsíða 48

46 ÍSLENZKAR LANDBÚNAÐARRANNSÓKNIR
A2 Ag X A5Ag mating was from a mating
on 13/1/1960, with date of lambing 5/6/
1960. One lamb, a white female. The sire
was No. 08017, the same as above, and tlie
dam No. 08082, black with white mark-
ings, genotype AgAgB^-SoSjj.
An accidental mating to a white ram
could easily explain this lamb.
Case 10. Mating A3A5 X A2A4.
One brown lamb.
The lamb was born on farm No. 5. Date
of mating 29/12/1959, date of lambing un-
known.
Two lambs, a black mouflon female and
a brown male, both with extensive white
markings.
Tlie sire was No. 01064, black badgerface
with white markings, genotype AgAgB^B^
S2S2. This was the only progeny of that
sire with unexpected colour.
The dam was ewe No. 05598, grey mou-
flon with white markings, genotype A2A4
B4B2S2S2. It was clear from the dam’s
parents that she did not carry the A6-
allele. On the other hand it is just possible
that she in reality was of genotype A±Ag
BiBoS2S2, and had been misclassified be-
cause of the extensive white markings. If
this was the case, the brown lamb could
well be expected from this mating.
The brown lamb itself might also have
been misclassified because of the wliite
markings, i.e. it could have been grey-
brown, and the grey pattern escaped de-
tection.
If the classification of both ewe and
lamb is correct, this is another example of
the loss of either the A2-allele or the A±-
allele by mutation to A5.
Case 11. Mating A4A5 X A5A5.
Wliite and grey mouflon
twin pair.
The lambs were born on farm No. 6.
Date of mating 1/1/1960, date of lambing
15/5/1960. Twins, white female and grey
mouflon male with white markings (colour
1144).
The sire was No. 06034, black mouflon
with white markings, colour 0431, geno-
type A^AgB^B^S^S^, and the dam No.
06137, brown, genotype AgAgB^B^S^S^.
As the white female lamb only develop-
ed scurs and not true horns, and both her
parents were horned that lamb is rnost
likely the progeny of a polled, homozygous
white ram used on the farm in that year.
The colour description of the male lamb
could have been faulty, the correct colour
being black mouflon with white markings.
Case 12. Mating A5A5 x A4A2.
One black lamb.
The lamb was born on farm No. 4. Date
of mating 6/1/1959, date of lambing 29/5/
1959. Twins, white male and black fernale.
The sire of these lambs was ram No.
04006, black with white markings, geno-
type AgAgB^BoSjjSo. He was very well
tested and never gave any other progeny
of unexpected colour.
The dam was ewe no. 04020, white,
genotype AiAoB^---------. In matings to
heterozygous white sires she produced 2
wliite and 2 grey lambs, and when mated
to AgAg-sires, excepting the mating in
1959, she produced 4 white and 3 grey
progeny.
l'he lamb in question could be a mis-
classification, but that is rather unlikely,
as the farmer would have discovered thev
grey colour in autumn ancl then kept the
larnb for breeding.
It could also have been a case of mis-
mothering, as several black lambs were
born on the farm in the same year. The
third possibility is that it was a loss of